Local access to data while roaming with a mobile telephony device

ABSTRACT

Apparatus for local access to data while roaming with a mobile telephony device at a roaming network. The apparatus is located at the roaming network and comprises a filter having a data packet or packet header inspection unit for inspecting packet information or headers to identify data packets addressed from the roaming telephony device for use via a home network data packet gateway, and a packet diverter for diverting at least some of the identified packets to a local data packet gateway; the filter setting up a diversion tunnel for additional packets of the same session for directly routing all packets of the identified session to the local data packet gateway. Mobile devices are today programmed to send data to their home network for browsing via the home network data packet gateway. The filter allows data to be redirected to the roaming network so that Internet browsing and like data uses can be carried out directly by the roaming user at less cost and greater efficiency and quality of service.

RELATED APPLICATIONS

This application is a National Phase of PCT Patent Application No.PCT/IL2010/001096 having International filing date of Dec. 30, 2010,which claims the benefit of priority of U.S. Provisional PatentApplication No. 61/291,961 filed on Jan. 4, 2010. The contents of theabove applications are all incorporated herein by reference.

FIELD AND BACKGROUND OF THE INVENTION

The present invention relates to local access to data while roaming witha mobile telephony device and, more particularly, but not exclusively tosuch access for Internet surfing and like data uses.

Data roaming in GSM and other 3G networks is based on the concept thatall data traffic is routed to the home network first, and then to thefinal destination. The SGSN (Serving GPRS Support Node) network coreelement in the roaming (visited) network receives the data traffic fromthe base station/base station controller, performs DNS resolution, androutes the traffic to the home network GGSN (Gateway GPRS Support Node).The GGSN allocates an IP address for the mobile device, and connects thesession to the service—the Internet, the so-called walled garden or homeportal network, or any other service. The GGSN may also performscharging for the data service, and charging may be either postpaid, viadata records, CDRs or OCS—an Online Charging System, or may be prepaid,achieved by interfacing with a prepaid system. Charging can also betriggered by the SGSN at the visited network, using CAMEL triggers sentdirectly to the home charging system. Such is mainly used for prepaid.

In the fourth generation or 4G LTE/EPC (4G) network, the situationremains basically the same. All roaming data is still to be directed tothe home network. In LTE voice is considered data as well, as LTE usesVoIP solutions such as SIP and IMS. However voice originated calls inroaming, that is MO calls, or Mobile originated calls, are notnecessarily routed to the home network first. Instead, they may berouted to the destination directly from the roaming network. Such directrouting actually preserves the situation in 2G/3G networks, where MOcalls in roaming are also not routed to the home network. Direct routingworks by building into LTE networks a configuration known as LocalBreakout, where data is identified as voice data, according to the APN(Access Point Name) of the voice application, and followingidentification is handled solely by the local network. However data notidentified as voice data continues to be sent to the home network asbefore, leading to greater cost, lower efficiency and lower quality ofservice.

The present inventors consider that the current situation in which datatraffic does go to the home network is going to change, as more datatraffic is used by roamers.

Home routing of data traffic indeed creates a severe quality of service(QoS) problem for the data traffic, due to the additional distance itpasses. In addition, the mobile operator is charged by the internationalcarrier for a GRX service (GPRS exchange routing).

As mentioned, LTE/EPC indicates the fourth generation (4G) of mobilenetwork to evolution. LTE (Long Term Evolution) concentrates on theradio part of the network, while EPC (Evolved Packet Network) refers tothe all-IP next generation core network. The network architecture maydrastically change while moving to all-IP. The traditional 2G/3Gfeatures of MSC/VLR and HLR are expected to disappear, replaced by newnetwork components: MME, Service GW and PDN GW.

The 3GPP LTE roaming standardization uses different architecturesrespectively for home routing and local breakout. Home routing requiresall data traffic to go to the home network first, and then to thedestination, as in the case of the legacy GSM and 3G. However sincevoice calls are data too (except for the CS fallback case), 3GPPpreserves the current mode for roaming MO calls (Mobile Originated)calls, so that the MO calls are not routed to the home network first.For this reason, the local breakout mode was defined, where the visitednetwork (VPMN) enables a local exit of voice sessions. The local exitrequires the VPMN to distinguish between voice and data sessions, andapply different routing rules, per the specific home network.

Voice calls originating in the roaming network are thus not routed tothe home network, unless of course this is the actual destination.Nevertheless, as data, such as packets for Internet browsing, is alwaysgiven a destination at the home network, such data is necessarily routedto the home network.

The 3GPP standard solution for charging the local breakout scenario isrelatively complex. The system requires that the PCEF unit, the Policyand Charging Evaluation Function, at the visited network, which has thehome network charging rules loaded, communicates with the home OCS(On-line Charging System) that does the actual charging. For the localbreakout scenario, the home OCS may perform real-time charging accordingto the visited network tariff plans and charges. In LTE networks thetariff plans and policies may dynamically change, and that requires thehome network OCS to adapt in real time as well.

Alcatel-Lucent (ALU) identified this problematic situation, andpublished an article proposing an improved solution. The paper, “OnlineCharging in the Roaming LTE/EPC Network”, was published in Bell LabsTechnical Journal 15(1), pages 115-132, at 2010. ALU proposes adding av-OCS, an additional OCS entity at the visited network which servesinbound roamers, and mediates with the home OCS. The v-OCS may be thefocal point for local charging, according to the VPMN charging plans,but always in communication with the h-OCS. The ALU solution imposes anew architecture at the VPMN and new interfaces to the home OCS, Ro′ andRc′, which are not standardized yet, and even more problematically,which requires modification to the home OCS as well.

SUMMARY OF THE INVENTION

According to one aspect of the present invention there is providedapparatus for local access to data while roaming with a mobile telephonydevice at a roaming network, the telephony device being associated witha home network separate from the roaming network, the apparatus beinglocated at the roaming network and comprising:

a filter having a data packet inspection unit for inspecting packets toidentify data packets addressed from the roaming telephony device foruse via a home network data packet gateway, and a packet diverter fordiverting at least some of the identified packets to a local data packetgateway;

the filter being further configured to set up a diversion tunnel foradditional packets having packet destination information correspondingto the diverted packets, the diversion tunnel being for locally routingthe packets having corresponding packet destination address informationto the local data packet gateway.

In an embodiment, the filter is configured to extract the packets from adata tunnel to the home data packet gateway and to create a continuationof the data tunnel to the home data packet gateway alongside thediversion tunnel.

In an embodiment, the filter is configured to initially divert packets,and to cancel the diversion when the diverted packets attract accessrefusals and to re-send the packets to the home data packet gateway.

In an embodiment, the home network provides a subscription-based dataservice accessible through a portal, wherein the packet diverter isconfigured to select between packets addressed for the subscriptionbased service and packets addressed for use outside of the subscriptionbased service, and diverts only packets intended for the outside usewithout the need for the home network subscription.

In an embodiment, the packet diverter is configured to carry out theselecting by determining whether the packet contains a URL that maps toa portal of the home network.

In an embodiment, the packet diverter is further configured to detectwhen diverted packets return a no access error, to cease to divertpackets corresponding to the no access error, and to re-send thecorresponding packets to their original address.

In an embodiment, the filter is contained in a GTP signaling relay.

Alternatively, the filter is contained in an MIP or a PMIP signalingrelay.

In an embodiment, data is channeled from the roaming mobile device tothe relay via a serving GPRS support node—SGSN, wherein a data packetgateway comprises a GGSN—the relay comprising an SGSN/GGSN emulator,emulating an SGSN to the home network GGSN and a GGSN to the roamingnetwork SGSN.

In an embodiment, the networks are all-IP networks wherein data ischanneled from the roaming mobile device to the relay via a servinggateway, and wherein a data packet gateway comprises a PDN gateway, therelay comprising an serving gateway/PDN gateway emulator, emulating aserving gateway towards the home network PDN gateway and a PDN gatewaytowards the roaming network serving gateway.

In an embodiment, the diverted packets are diverted towards localbreakout at a local PDN gateway alongside voice packets.

In an embodiment, the packet diverter is configured to divert byreplacing the address of the home data packet gateway or a nameidentifying the home gateway with the address of the local data packetgateway within the inspected message.

An embodiment may comprise a packet return path for data packets to theroaming mobile user, the return path configured to set all returningpackets to a given roaming mobile user to a same IP address.

In an embodiment, the diverted data packets are notified to the homenetwork for charging.

In an embodiment, call data records are sent to the home network for thecharging.

An embodiment may comprise an OCS relay to decide whether to charge theroaming user at the home network or at the local network.

In an embodiment, the decision to charge is based on the presence orabsence of a subscription of the roaming user at the local network.

In an embodiment, a charging relay is provided at the local network formanaging charging for the data, the charging relay being associated withthe filter to send charges for the diverted data to the local networkand to send charges for other data to the home network.

According to a second aspect of the present invention there is provideda method for providing local access to data while roaming with a mobiletelephony device at a roaming network, the telephony device beingassociated with a home network separate from the roaming network, themethod being carried out at the roaming network and comprising:

inspecting packets to identify data packets addressed from the roamingtelephony device for use via a home network data packet gateway;

diverting at least some of the identified packets to a local data packetgateway; and

setting up a diversion tunnel for additional packets having packetinformation corresponding to the diverted packets, the diversion tunneldirectly routing the packets having the corresponding packet informationto the local data packet gateway.

The method may comprise extracting the packets from a data tunnel to thehome data packet gateway and creating a continuation of the data tunnelto the home data packet gateway alongside the diversion tunnel.

The method may comprise:

initially diverting packets as a default setting; and

cancelling the diversion when ones of the diverted packets attractaccess refusals,

and following the cancelling, sending the ones of the diverted packetsto an original destination.

The home network may provide a subscription data service accessiblethrough a portal, and the method may comprise:

selecting between packets addressed for the subscription data serviceand packets addressed outside of the subscription data service; and

diverting only those packets addressed outside of the subscription dataservice.

The method may comprise carrying out the selecting by examining layer 7data of the packet to find a URL and determining whether the URL maps toa portal of the home network.

In an embodiment, the diverting comprises exchanging the address of thehome data packet gateway or a name identifying the home gateway with theaddress of the local data packet gateway within the inspected header.

The method may provide a packet return path for data packets to theroaming mobile user, the method comprising setting all packets in thepacket return path to a respective roaming mobile user to a same IPaddress.

Unless otherwise defined, all technical and scientific terms used hereinhave the same meaning as commonly understood by one of ordinary skill inthe art to which this invention belongs. The materials, methods, andexamples provided herein are illustrative only and not intended to belimiting.

The word “exemplary” is used herein to mean “serving as an example,instance or illustration”. Any embodiment described as “exemplary” isnot necessarily to be construed as preferred or advantageous over otherembodiments and/or to exclude the incorporation of features from otherembodiments.

The word “optionally” is used herein to mean “is provided in someembodiments and not provided in other embodiments”. Any particularembodiment of the invention may include a plurality of “optional”features unless such features conflict.

Implementation of the method and/or system of embodiments of theinvention can involve performing or completing selected tasks manually,automatically, or a combination thereof.

Moreover, according to actual instrumentation and equipment ofembodiments of the method and/or system of the invention, severalselected tasks could be implemented by hardware, by software or byfirmware or by a combination thereof using an operating system.

For example, hardware for performing selected tasks according toembodiments of the invention could be implemented as a chip or acircuit. As software, selected tasks according to embodiments of theinvention could be implemented as a plurality of software instructionsbeing executed by a computer using any suitable operating system. In anexemplary embodiment of the invention, one or more tasks according toexemplary embodiments of method and/or system as described herein areperformed by a data processor, such as a computing platform forexecuting a plurality of instructions. Optionally, the data processorincludes a volatile memory for storing instructions and/or data and/or anon-volatile storage, for example, a magnetic hard-disk and/or removablemedia, for storing instructions and/or data. Optionally, a networkconnection is provided as well. A display and/or a user input devicesuch as a keyboard or mouse are optionally provided as well.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention is herein described, by way of example only, withreference to the accompanying drawings. With specific reference now tothe drawings in detail, it is stressed that the particulars shown are byway of example and for purposes of illustrative discussion of thepreferred embodiments of the present invention only, and are presentedin order to provide what is believed to be the most useful and readilyunderstood description of the principles and conceptual aspects of theinvention. In this regard, no attempt is made to show structural detailsof the invention in more detail than is necessary for a fundamentalunderstanding of the invention, the description taken with the drawingsmaking apparent to those skilled in the art how the several forms of theinvention may be embodied in practice.

In the drawings:

FIG. 1 is a simplified diagram illustrating a relay device located at aroaming network according to the present embodiments;

FIG. 2 shows the relationship of the relay of FIG. 1 to both the homeand roaming networks and various gateway components therein;

FIG. 3 is a simplified flow diagram showing process flows using therelay of FIGS. 1 and 2;

FIG. 4 is a simplified flow chart illustrating the outgoing flow fromthe mobile device according to the present embodiments;

FIG. 5 is a simplified diagram showing the incoming flow correspondingto that of FIG. 4, according to the present embodiments;

FIG. 6 is a simplified block diagram of the relay of FIG. 1 set up on a4G network according to an embodiment of the present invention; and

FIG. 7 is a simplified diagram illustrating charging components forDiameter based charging on a 4G network.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The present embodiments provide local routing or local breakout forroaming data services as well as voice. The present embodiments providea system and method for enabling local management of data traffic, andin the case of the LTE network, local breakout of roaming data ingeneral. Embodiments enable the visited network to manage relevant partsof the roaming data by itself, while other parts can still be managed bythe home network.

Local breakout LBO fundamentally changes the situation for data roaming.So far in GPRS networks, the data has always been routed to the homenetwork. However, if the local breakout system can apply itself to dataas well, then a cheaper and higher quality system of data roaming may beprovided.

The idea of a new product according to the present embodiments, whichmay be referred to as Local Roaming GPRS or (LRG) is to provide localaccess to GPRS while in roaming. The same concept is applied for EPC/LTE4G networks, as explained below, and these networks do not use GPRS.Thus GPRS is mentioned herein as an example only. That is theembodiments may provide an IP connection for the roaming subscriber viathe visited network directly, without the need to route the data to thehome network first. The Internet connection may be provided with a muchhigher QoS, and potentially at a much lower cost. In fact, the servicecan be provided at a local GPRS tariff, i.e. the same tariff used forlocal network subscribers. This service may then provide realcompetition for WiFi at hotels for example, for travelers. However thetariff is a matter for the operator, keeping in mind that data roamingis still very expensive, despite attempts at cost reduction in Europe,and prevents roamers from consuming more data.

There are two main options for charging:

(1) keep charging via the home network

(2) use a local prepaid or postpaid account in the visited network.

The first option requires coordination between the visited and the homenetworks. Call Data Records (CDRs) may be sent from the visited to thehome network—as for voice calls. Prepaid users can be charged on-linevia CAMEL or using proprietary solutions. The second option does notrequire any coordination with the home network. The visited network canoperate the service on its own, but it needs to market the service tothe inbound roamers, and convince them to purchase local prepaid cards,or use a credit card for a postpaid account, that is not to pay inadvance, but provide the credit card details to the roaming network foropening a postpaid account, or by any other method.

The charging may be differentiated as well, and voice charging may behandled by the visited network in the first place and then handed overto the home network, or perhaps handled locally—potentially as a localprepaid account. The local charging poses new requirements for the VPMN,and new opportunities as well.

In the following, a prepaid mode is discussed by way of example only,for the various credit solutions that may be used in the roaming networkincluding postpaid via credit cards, and others. An Online ChargingSystem (OCS) may be used for charging the inbound roamer, in the visitednetwork.

The following discussion refers to GPRS and GRX (GPRS Exchange Routing)which relate to 2G/3G GPRS networks, but these are given only by way ofexample. The discussion also includes LTE networks. In either case theGTP (GPRS Tunneling Protocol) may be used as a carrier for IP traffic.In LTE networks, MIP (Mobile IP) or PMIP can be used as an alternativeto GTP, hence the present embodiments covers both GTP and MIP/PMIP.

In the LTE case, instead of SGSN and GGSN, which relate to 2G and 3Gnetworks, such components as the “Serving Gateway” (S-GW) and PDNGateway (PDG), provide the corresponding functions respectively.

The following discusses the invention by way of an example based on GSM.However the invention is equally applicable to CDMA.

The principles and operation of an apparatus and method according to thepresent invention may be better understood with reference to thedrawings and accompanying description.

Before explaining at least one embodiment of the invention in detail, itis to be understood that the invention is not limited in its applicationto the details of construction and the arrangement of the components setforth in the following description or illustrated in the drawings. Theinvention is capable of other embodiments or of being practiced orcarried out in various ways. Also, it is to be understood that thephraseology and terminology employed herein is for the purpose ofdescription and should not be regarded as limiting.

Reference is now made to FIG. 1 which illustrates apparatus for localaccess to data while roaming. A mobile telephony device 10 operates at aroaming network 12, which now becomes the roaming user's local network.The telephony device is associated with a home network (FIG. 2) which isseparate from the roaming network at which the device 10 is registered.

The apparatus comprises a filter 14, which has a data packet or packetheader analysis unit 16. The analysis unit 16 looks generally at theheaders of packets passing the filter to identify data packets addressedfrom the device 10 for data use via a home network data packet gateway.Such data is generally found in the header but may be located elsewhere,and the filter may be designed to search for the information asappropriate in any given case. Such data packets are thus identified asdata packets, meaning packets for Internet services, such as email orbrowsing or datastreaming or other network services, or intranetservices or the like. A packet diverter 18 diverts some or all of theidentified packets to a local Internet data packet gateway which may bea local breakout gateway in the 4G system.

The filter 14 may set up a diversion tunnel 20 for additional packetshaving packet headers corresponding to the above diverted packets.Generally a particular data session or service involves multiplepackets, having in common similar entries in particular parts of theheader. The tunnel ensures that once the first packet of a session hasbeen identified then later packets belonging to the same session can beidentified more simply and directed to the same output. The diversiontunnel 20 thus routes those packets having packet headers correspondingto earlier identifications directly to the local data packet gateway.

It is noted that, in addition to diversion tunnel 20 to the localgateway, there is a diversion tunnel 21 to the home gateway as well. Thestarting point for the GPT tunnel is the SGSN in case of GPRS traffic,or Serving GW in case of LTE. A second tunnel is needed at the relaybecause it is not possible to chain end points for the data tunnel. Assoon as the relay receives the data it makes itself a tunnel end point,and in order to relay it to the original destination it becomesnecessary to open a new tunnel. This is because GPT data is alreadytunnel data.

That is to say, an initial GPT tunnel to the home gateway, which was setup by the V-SGSN, is cancelled at the relay since the relay needs toaccess the packets. The cancelled tunnel thus needs to be recreated atthe relay, and the relay emulates the SGSN starting point for tunnel 21,as well as creating diversion tunnel 20. Hence the relay forms two newtunnels from the single GPT tunnel.

It is noted that the packets do not always contain the IP address of thefinal destination. Often they may contain a name, an APN, which has notbeen resolved yet by the local DNS, and may be resolved later, in ahigher level DNS, at the international carrier GRX for example. It isalso noted that the local gateway will always be an IP address, sincethere is generally no further name resolution in the local network.

The home network typically provides its own subscription-based orinternal data service, which is accessible only through its own portal,a set up known as a walled garden. If the data packet requires a sessionwithin that walled garden then it needs to be sent to the home networkwithout being diverted, since such services are only accessible from thehome network gateway. Thus the packet diverter may look for packetshaving destination addresses within the home network, say by comparing afinal destination URL or APN or IP address in the header to the network.Then those packets addressed for the subscription based data service andpackets addressed for use outside of the subscription based home networkdata service can be distinguished. The packet diverter may then divertonly those packets intended for use outside of the subscription baseddata service.

Thus the packet diverter may determine whether the packet headercontains a URL that maps to the Internet portal of the home network andif so then the packet is not diverted.

If a walled garden destination is erroneously not identified and apacket intended for such a destination is diverted to the local gatewaythen it will not be given access to to the walled garden and a No Accesserror will be returned. Thus, as a fallback position, in case a walledgarden destination is erroneously not identified, the packet diverterlooks for diverted packets that return a No Access error or a similarerror code. The diversion of the corresponding session may then becancelled, and the data may be re-routed to the home gateway.

In one embodiment, all sessions are by default directed to the localV-GSSN. Then, if a No Access error is returned, it is assumed that theaddress is part of the walled garden of the home portal. Thus when a NoAccess error is received, the session is then sent directly to the homeportal.

In another embodiment header data is analyzed and the session is sent tothe walled garden or to the local gateway as appropriate. However, ifthe header is not specifically recognized as being directed to thewalled garden then the default setting of the local V-GSSN is used.Again, if a no-access error is received then the session is redirectedto the walled garden.

Reference is now made to FIG. 2 which is a simplified block diagramshowing elements of the roaming or visited network and the home network.Data from the roaming device 10 is directed at roaming network 12 to aserving GPRS support node of the visited network, V-SGSN server 30.

The filter 14 may be contained in GTP signaling relay 32, and selectssome of the sessions for diversion to the roaming network V-GGSN 34 toprovide a local data service, and lets the remainder of the datacontinue to the home network 36 and the H-GGSN 38. Selecting may beaccording to the principles already discussed.

As an alternative to a GTP relay, the filter may be contained in an MIPsignaling relay—depending on the details of the roaming network.

Within the system, the SGSN 30 is the switch at the visited network thatreceives data from the mobile device. The SGSN conventionally sends thedata to the GGSN 38 which is always at the home network. All datarequiring Internet access is conventionally required to pass through theGGSN 38. Between the SGSN and the GGSN, packets are passed using theGTP—or GPRS Tunneling Protocol. GTP keeps the data in the form of IPpackets but packages them securely. Once reaching the H-GGSN the datamay remain within the walled garden of the provider—via an Internetportal, or access may be allowed to the external Internet.

Thus, as per the convention, the data in the present embodiments ischanneled from the roaming mobile device 10 to the SGSM 30. Howeverunlike the conventional setup, the GTP data sent on by the SGSM 30 isintercepted by GTP relay 32. The SGSM does not know about the relay andexpects to communicate with a packet data gateway or GGSN. Hence therelay includes an SGSN/GGSN emulator, emulating an SGSN to the GGSN, andalso emulating a GGSN to an SGSN for the reverse direction. Thus bothSGSN and GGSN communicate with the relay in the normal way that theywould communicate with each other. The SGSN and GGSN do not need anychanges to be made to themselves.

FIG. 2 illustrates a 3G network. For a VoIP or LTE 4G network, data ischanneled from the roaming mobile device 10 to the relay via a servinggateway SG, and the Internet data packet gateway comprises a PDNgateway. In this case the relay includes a serving gateway/PDN gatewayemulator which emulates a serving gateway to a PDN gateway and a PDNgateway to a serving gateway.

The diverted packets may be diverted towards local breakout at a localPDN gateway alongside voice packets. Typically the voice packets in theLTE network are directed automatically towards local breakout as theywould never have been addressed to the home network in the first place.An LTE network is shown in FIG. 7 and discussed in greater detailhereinbelow.

Returning to the filter, and the packet diverter 18 may carry out thediversion process by exchanging the address of the home data packetgateway with the address of the local data packet gateway of the roamingnetwork within the inspected header. The headers include an APN oraccess point name to get them from the cellular device to the SGSN. Anexample may be Example “Internet”@cellcom.gprs.org“<service>@provider.gprs.com—The APN may be checked at DNS 40 of thelocal operator. The packet further includes the address of the homenetwork GGSN 38, to which the data is forwarded. However relay 32exchanges the address of the home network GGSN 38 with that of the localnetwork GGSN 34.

A packet return path allows data packets to return to the roaming mobileuser in response to browsing requests etc. The packets in the returnpath have different destinations depending on whether they have beenrouted via the home or the roaming network. However the mobile device isonly set up to deal with a single address. Thus the return path includesfunctionality to set all returning packets to a given roaming mobileuser to the same IP address.

The IP address management is a further example of managing two tunnelsfrom the relay, to the local and home gateways, with a single IP addresstowards the device. The initial IP address may be assigned by the localIP gateway, and the handset may obtain a local IP address. Then, we mayreplace the home IP address with the local IP address every time thehome gateway sends a data packet towards the handset. By the same tokenalso it is possible to replace the local IP address with the home IPaddress every time packets containing local IP address are sent to thehome gateway.

In one embodiment, diverted data packets are notified to the homenetwork for charging, for example using call data records (CDR)

In an alternative embodiment, an OCS relay may decide between chargingthe roaming user at the home network or at the local network. Thedecision may be based on whether or not the user has an account at theroaming network.

In the case of LTE, everything coming from the mobile telephone is sentin IP data packets, including voice. However the voice and other datasuch as browsing data are distinguished in that the voice packets areaddressed for local breakout and the data packets are addressed to thedata gateways.

In general MO voice calls go directly to local numbers without goinghome. LTE allows the voice data to go to a local gateway—the localbreakout referred to above, and sends data to the local PDN gateway. Thevoice packets generally have a specific APN so that they can be easilyidentified and sent to the local PDN node.

The LTE network has a similar GTP (GPRS Tunneling Protocol) protocolcarrier for data sent to the home network from the visited network andcan apply the same criteria as discussed above, to choose between localand home network routing of the session, and thus to send appropriatedata packets to the ePDG at the local or home networks. LTE networks canalso use MIP (Mobile IP)/PMIP (Proxy Mobile IP) as a protocol carrier,instead of GTP, notably in the USA former CDMA countries.

The standard charging system for roaming in LTE assumes that the visitednetwork PCEF (charging component) communicates with the home network OCS(On-line charging system), in case of local breakout (where the voice isfully controlled by the visited network). This is a complex solution,assuming close coordination between these two systems.

While using local roaming data, it may make sense to use a local prepaidaccount. A local prepaid account implies that the roamer is charged bythe roaming network directly, the same network that provides the localdata access. Such a solution may be implemented by an OCS diameterrelay. An OCS diameter relay may intercept all traffic directed to thehome OCS system, and may make a decision about whether to charge thesubscriber via the home network or via a local prepaid system. The OCSrelay is aware of whether any particular roaming user has a localprepaid account or a local postpaid account (via credit card forexample) and thus is able to charge the card or account withoutinvolving the home network at all. If using the OCS diameter relay inthis way then a Diameter proxy agent is required to change thesubscriber identity for the local account, since this is the role of aDiameter Proxy.

It may be that the home and local networks apply different quality ofservice (QoS) rules for data use. For example the two networks mayallocate different bandwidths. For example the home network may supply a1M bandwidth whereas the local network gives only 0.5M. A systemparameter may be available to choose between the two options. If theuser has paid the local network through a local account, it may be giventhe local network rules, although the user may be offered a higher levelof service at a different tariff. The usual preference amongst operatorsis to provide the home network rules, whether they are better or worse,as this is what the user is used to.

The V-PCRF component applies the standard QoS policies as defined forthe given network. An application function (AF) can then be provided asan override to give a different QoS. The AF may include a local prepaidApp function. The AF talks to both the V-PCRF and to the OCS diameterrelay in order to provide the updated quality of service.

Embodiments of the present invention may provide any one or more of thefollowing features:

The embodiments may improve QoS for data roaming since they obviate theneed for data roaming to pass the home network data gateway. Theembodiments may enable high speed video & internet at the same level ofquality that the user is used to at his home-network.

Data roaming may be provided at a local tariff rather than anInternational tariff, depending on the charging policy of the localnetwork.

The use of data roaming may encourage roaming users to make use of thedata capabilities of their mobile devices rather than pay for say hotelWi-Fi.

Roamers are in any event more willing to pay for high quality Internetaccess than for the lower quality enforced by the need to use the homenetwork gateway.

The embodiments preserve access to the walled garden home portal foroperator content that the subscriber is used to accessing.

For the operator, the present embodiments may reduce operational cost,save GRX (GPRS Exchange routing) charges, and may separate Internetaccess from the home portal or walled-garden, allowing the home portalto be accessed in the traditional way.

Billing can be left to the home network, unless the local prepaid systemis selected by the user, and the service can be marketed to selectedgroups of subscribers.

The solution can be particularly of interest to specific profiles. Forexample business/corporate customers are heavy consumers of email andbrowsing options. Data card holders may be offered a special package forroaming, and generally heavy 3G consumers—such as users of specificmobile handsets users may appreciate a special package for roaming.

Service can be offered to inbound roamers from specific partnering homenetworks, say where the billing is coordinated with the home network, orwhere the home network agrees to service promotion via SMS

The present embodiments provide for a platform to be installed at thevisited or roaming network, as per FIG. 3. The platform provides a GTPrelay, emulating an SGSN towards the real GGSNs, and emulating an SGSNtowards the real V-GGSN. The visited network SGSN thinks it is routingtraffic to the H-GGSN but actually the traffic goes to the relay whichin turn decides whether to route the traffic to the V-GGSN or to thehome H-GGSN. The traffic that is routed to the relay may be all datatraffic, or data traffic whose home network is in the scheme, or datatraffic of users who qualify for the scheme, depending on how the systemis set up. The GTP relay analyzes the packet header for sessioninformation and determines if it should intervene or not. If thesubscriber is subscribed to the service and the APN does not indicates aneed for the home network walled garden, there the relay may intervene.In that case the GTP relay acts as an SGSN and opens a new transactiontowards the local V-GGSN. Otherwise, the GTP relay relays thetransaction to the home GGSN. The platform is therefore a GTP Relay(GTP=GPRS Tunneling Protocol), a signaling relay which can intercept,open and modify GTP transactions.

After modifying the destination address to the local V-GGSN, the relaymay create a new PDP (Packet Data Protocol) context, i.e. initiate a newsession towards the V-GGSN, acting as an SGSN. It is not possible tochain GGSNs; the GGSN is a termination point for the PDP transaction.Hence, the GTP relay may emulate what is termed a skim SGSN, that is anSGSN supporting only the commands required for the specificmanipulations in question.

In the return direction, the GTP relay receives messages from the GGSN,and transmits them to the original SGSN. In this case, the GTP relay mayemulate a GGSN, and may modify the returned IP address and transactionID back to the originals prior to modification for sending to theV-GGSN.

Reference is made once again to FIG. 2, which illustrates the networkarchitecture of an embodiment of local roaming GPRS (LRG).

The GTP relay platform 32 may be installed at the VPMN. There is no needfor any platform or other modification in the home network.

The GTP relay may implement the following (high level) flow:

The V-SGSN may route inbound roaming data traffic via the GTP relay as aresult of modifying the SGSN IP routing table. The relay may determineif there is a need for intrusive handling. For example, if the homenetwork is not relevant, or the subscriber is not subscribed to theservice, or the APN (Access Point Name) identifier of the service is thehome walled garden, the session may be relayed to the home GGSN, withoutany modification.

If none of the above applies, then the relay may create a new PDPcontext towards the local GGSN, while acting as an SGSN. In this case,replies from the local GGSN may reach the relay platform in the returndirection, and the relay may then modify the local GGSN IP address andtransaction ID back to the original, while acting as the home GGSNtowards the local SGSN, the local SGSN having initiated a transaction tothe home GGSN.

In both cases, the transaction ID may be kept, for handling subsequentmessages on the same route. The subsequent messages need not contain alldetails since the details are contained in the initial PDP context.

For each device, the relay creates two kinds of PDP contexts, one to thelocal V-GGSN and one to the home H-GGSN, whilst acting as an SGSN forboth. Thus, APNs may serve both walled garden and local access. Anyindividual session is thus analyzed to determine dynamically, based onthe URL, whether to route locally or via the home network. The relaymanages two IP addresses, but provides only one of them to the mobiledevice, which would not be able, at least without modification, to dealwith two IP addresses.

In the LTE case, the separation between VoIP and data may be based onAPN. Clearly all VoIP data can be sent to local breakout, if identifiedby a dedicated APN, such as “IMS”. In greater detail, there are twoparameters that may be used for distinguishing between VoIP anddata,—APN and URL data. But a problem arises in that there is nospecific APN associated with any data application. That is to say thereis no standard. Rather the APN is operator specific—since it is onlyused to get to the home gateway, the operator tends to use its ownlanguage. For the voice, they define a standard APN—“IMS” to distinguishvoice from data, and thus an APN is sufficient to distinguish voice fromdata. However, the APN does not distinguish between for different datatypes. Therefore the present embodiments may identify the walled-gardendata, and route all the rest to the local gateway using URL analysis.However the URL data is at a deeper level within the packet, typicallywhat is known as level seven. The URL data is thus used after the APN,to identify within the APN how to divert the data. A URL-basedseparation enables the user to access the home network for specific websites, those which are part of the walled garden, for example, but toenjoy local access to the Internet for most of the web sites. Reroutingis not restricted to identifications made at the beginning of a session,but can also be carried out later on during the session and splittingthe session between the home and visited networks. Thus a first part ofthe session is charged by the home network, and the second part by thevisited network.

In one embodiment, an SS7 probe 42 is used to monitor roaming activityand to indicate the arrival of an inbound roamer. The probe may allow atrigger, from the roaming registration, to send a message to the newlyregistering roamer to offer the service to the roamer. The probe maylikewise allow a trigger for roaming cancellation which can be used asan alert to stop the service. An SMS interface may be used with theinbound roamers to manage opting in and out for the service using theinput from the probe.

The platform may be provided with web based provisioning, to allow theoperator to carry out system configuration.

Reference is now made to FIG. 3, which is a simplified flow diagram ofthe system, showing data flow including service flow.

The figure covers the two directions of flow, that is

(a) The flow from the visited network SGSN 50 to a GGSN 52 (either localor home)—the outward direction from the mobile device, and

(b) The flow from the GGSN 52 (either local or home) to the visited SGSN50 and from there back to the mobile device.

When a new packet is received from the mobile device, a first task is todecide if this is a new session. A second task is to determine whetherthe user is subscribed to or eligible for the service. These tasks maybe carried out at the GTP header decoder 54.

If the local data service is required then the core engine 56 of therelay platform changes the address. The address to be changed may be theAPN or may be what a local DNS has swapped for the APN, or may be a URLincluded in the header.

A message comes from the SGSN 50 so the relay acts as a GGSN 52 tocorrectly handle and acknowledge the message. To do this the relayincludes GGSN emulation or, as shown in the figure, a GGSN full decoder58.

The packet now exits the core engine 56 with a gateway IP address whichmay be either the local or the home GGSN.

A reply is then received.

The reply comes from one or other of the GGSNs 52 so the relay has toinclude SGSN emulation, or an SGSN full decoder 60. No decisions areneeded for the return leg as all data goes to the mobile device. Howeverthe data has to be sent with a single IP address whereas it arrives witheither of two addresses due to the two different sessions—home networkand local network. The sessions may be kept transparent to the mobiledevice which expects a single address and thus should not see that twosessions are running.

In the outward direction, packet header inspection looks for a URL andthus reads layer 7 data from the packets. A GTP layer 7 decoder 62 isused.

Layer 7 checks the URL to see if it maps to the network indicated as theuser's home network, and if it does then not to divert the packets inthe first place, thus avoiding having to wait for an access error inthose cases. Once a session has been identified, then all packetsbelonging to that session are recognized as an existing session and arerouted via a relay manager 64 to either the visited or the home network.without any further intervention beyond replacing IP addresses back andforth, as explained hereinabove.

MAP probing to offer the service to new arrivals is provided as per box68. An SMS interface for notifications is provided in box 70, where thenotifications may be to do with offering the new service or could relateto the service in general. Web provisioning for the operator is providedin box 72.

The flow provides three ways to pay for the service. In box 74 the localprepaid system allows the user to purchase a card with a number. A localprepaid solution allows all charges to be settled at the visitednetwork. The necessary interface with the local prepaid system, via INor proprietary interfaces is provided through Local Prepaid adaptor 74.

Box 76 allows charging via the home OCS (online charging system) througha Diameter adaptor. Note that in pre-LTE networks, Diameter is not thecross-network protocol, and is used only between the GGSN and thebilling system. Hence a Diameter adaptor was needed to connect to thehome charging system. In order to provide on-line charging an interfacemay provide direct access to the home OCS (On-line Charging System).Such an interface may be located between the relay platform acting as aGGSN and the home network OCS. To achieve such an interface, DiameterAdaptor 76 is connected to the core engine unit.

Box 78 provides for charging through the Camel System. Both Diameter andCamel can support charges in real time which appear on the regular billprovided from the home network. Box 80 shows Call Data Records (CDR)being sent from the core engine to the home network for the purpose ofnon-real-time or near-real-time charging at the home network. For homenetworks that do not support Diameter and OCS, CAMEL triggers towardsthe home prepaid-SCP platform allow for support of prepaid users. Therelay platform then acts as an SGSN, issuing CAMEL triggers. TheGPRS-CAMEL adaptor unit 78 may implement such support.

The SGSN-to-GGSN Direction:

Referring now to FIG. 4, the SGSN to GGSN data flow direction is shownin greater detail. When initiating or continuing a data session, thesignaling is routed from the V-SGSN of the visited network to the relayplatform—100. For a new session a new PDP-context is created by theSGSN. That is to say, the real SGSN creates a new context, for a newsession, for example when the user starts the browsing session. Thesession however is terminated by the relay, acting as a GGSN terminationpoint. Then the relay creates a new context towards the real GGSN,acting now as an SGSN. This new context may be kept with other contexts,created by the relay. For an existing session, an on-going datatransaction is set up—102.

The GTP header decoder analyzes the GTP header of the incoming messageand determines if the message comes from the SGSN or a GGSN—104. Theflow of FIG. 4 deals with a message received from the SGSN, while thatof FIG. 5 deals with the other direction. As per the above, the GTPheader decoder 54 determines if the current packet is part of a newsession (a PDP-Context-Create message) or of an existing session. In thecase of an existing session the decision about local/home routing hasalready been taken, and the message is transmitted to the Relay Manager64. In the case of a new session the flow jumps to 110. At 110 thecontrol may be handed over to the GGSN GTP full decoder 58, for furtheranalysis.

For a known session or context the Relay Manager utilizes the previousdecision according to the tunnel-ID—106. For home GGSN routing, themessage is relayed directly, without modifications 108, except for minoraddress modifications etc. For local GGSN routing, the control is givento the GGSN GTP full decoder 58, for further analysis 110, as mentionedabove.

The GGSN GTP full decoder 58 performs full decoding of the GTP message,acting as a GGSN.

The control is forwarded to the GTP decision maker 82. The decision asto where to forward the session—112, may be based on two mainparameters: the IMSI (identity) of the subscriber and the APN (theapplication to be used). In addition, the URL may be used, if thelayer-7 data is decoded as well. If the subscriber has an opt-in to theservice, and if the APN indicates that the local GGSN can serve thesubscriber (such as in the case of APN==internet), the transaction isrouted to the local GGSN. Otherwise, it is routed to the home GGSN.

Control is placed in the hands of the Core Engine unit 56. The coreengine becomes the session manager for all sessions going into or out ofthe GTP layer. In the flow described so far, the core engine unit mayemulate an SGSN towards the local GGSN. In the case of a newtransaction, the core engine may create a new PDP-context, allocating anew tunnel-ID. A new transaction and corresponding allocation of atunnel ID is something which may take place once per every session. Thenew tunnel ID is then provided to update the Relay Manager, so that nexttime the same header appears the ID will be automaticallyrecognized—114. The new transaction defines either local 116 or homeservice 118.

In the case of an existing transaction where the tunnel ID defines localservice, the core engine directs the transaction towards the local GGSN,modifying the relevant parameters such as by replacing the original SGSNaddress with its own address—108. Finally, the core engine invokes theSGSN GTP encoder, in order to create and send an SGSN-like message tothe local GGSN.

The core engine unit and the decision maker unit may use the subscriberand service provisioning database 83 for relevant data, say to find outwhether the subscriber is eligible for the service.

The SGSN GTP encoder unit 84 may encode an SGSN-like message and sendthe message to the local GGSN, acting as an SGSN.

The core engine unit may also invoke the CDR controller 80.

The GGSN-to-SGSN Direction:

Reference is now made to FIG. 5 which is a simplified schematic flowchart illustrating the flow when the data packets are traveling in thereverse direction, that is back to the mobile device. In this case thetransaction is not new, as it arrives from a GGSN—120, and the GTPheader decoder 54 may transmit the transaction to the SGSN GTP fulldecoder unit 60, as the relay is now acting as an SGSN.

The SGSN GTP full decoder 60 fully decodes the message—122, andtransmits it—124—to the Core Engine 56, which performs the mainprocessing in the present flow as well.

If the transaction has arrived from the local GGSN, the IP address ofthe local GGSN and the tunnel ID may be replaced with the address of thehome GGSN—126. Thus the local routing is rendered transparent to thelocal SGSN which is to receive the message.

If the transaction has arrived from the home GGSN, it may then berelayed to the local SGSN unchanged except for minor modifications tothe IP address—128. However encoding for the GGSN emulation—130 may berequired.

The GGSN GTP encoder 86 may create the GGSN-like messages, to emulate aGGSN, towards the local SGSN.

Reference is made again to FIG. 3. A further flow deals with the casewhere APN analysis is not sufficient to determine whether to selectlocal or home routing. A scenario of a mixed home-local session isprovided. The user may start the data session at the home operatorportal, the walled garden, and then access the internet from the portal.Two separate sessions may handle the case, where the walled gardensession is managed by the home GGSN, and the internet by the local GGSN.There is a need therefore for a URL analysis, rather than just an APNanalysis since the APN in such a case would always point to the homenetwork even though the user is now browsing outside the walled garden.

The GTP layer-7 decoder may further decode the layer 7. Layer 7 containsthe URL of the session and additional parameters at that level, andrequires a complex analysis unit.

After decoding at the layer 7 decoder 62, the message may be forwardedto the layer-7 decision maker 88, which determines the local or homerouting based on various relevant parameters, for example by comparingthe URL to the home network of the mobile device.

The message may be transferred to the core engine 56, which now handlestwo sessions in parallel. There is a need to assign two tunnel-IDs, andhandle a unified session context for the two sessions.

Reference is now made to FIG. 6, which is a simplified diagramillustrating an LTE network according to an embodiment of the presentinvention. GTP relay 200 is located at the visited network VPLMN anddecides whether to route traffic from serving gateway 202 to ePDG 204 ofthe visited network, or to PDN gateway 206 at the home network HPLMN.The operator's subscription-based services or walled garden 208 may byway of example be accessible from the home PDN gateway 206, althoughsuch is a matter for the operator to decide.

Charging using Diameter and LTE Networks

Reference is now made to FIG. 7 which is a block diagram of the chargingcomponents of an LTE or fourth generation 4G network. FIG. 7 shows thebasic network with additional components required for data chargingaccording to the present embodiments. In order to implement a localprepaid solution for inbound roamers, the local prepaid system used bythe domestic (local) subscribers may be used. However there is a need tocouple the roaming identity with a local identity, associated with alocal prepaid account. Such coupling may be implemented by a relayplatform.

In order to implement the above, Diameter Relay Agent 150 is able tocontrol diameter charging messages going to the home OCS, and determinewhich messages can be routed to the local prepaid system. For themessages going to the local OCS 152, there is a need to replace thesubscriber identity inside the messages, so the local prepaid system canhandle a local identity, according to the local tariff. The Proxy OCS154 may used to actually modify the messages, as this is the role of theDiameter proxy, and may also proxy the active pairs of identities forthe active sessions going on with the OCS(s) in order to increaseefficiency.

The system has two main components, the OCS Diameter Relay 150, and theOCS Diameter Proxy 154 and interfaces with system management for thelocal roaming prepaid service.

The OCS Diameter relay component 150 relays all Gy messages, or inalternative embodiments Ro and Rc messages going from the V-PCEF 156,the visited network policy and charging gateway and H-OCS 158,determining which should be handled by the local prepaid system. Thesemessages may be relayed to the local OCS 152 after replacing the roamingidentity of the subscriber with a local identity. The actual replacementmay be done by the OCS proxy 154, as discussed below.

The relay platform may intercept all Diameter messages, going to aspecific home network (or all home networks), enabling the examining ofmessage content, and routing the message either to the home network OCSor local OCS.

The relay may fetch and analyze subscriber identity, for example theIMSI, from the Diameter messages, and compare against the local prepaidsubscriber database/proxy server. If a local prepaid roaming user isidentified, the message is handed over to the OCS Proxy component 154for replacing the roaming identity and manipulating the message contentaccordingly. The same manipulation may also be provided for messagesgoing back from the local OCS to the core network, replacing the localidentity with the roaming identity. There is also an option to splitbetween the local and home OCS during a session, which is discussedhereinbelow.

The OCS proxy 154 may make actual replacements in the message content,and may also proxy the active couplings between roaming and localidentities, by keeping all modified portions of the messages in thecache, in order to save processing time.

The OCS proxy 154 may then check whether this is the first time such anold/new pair of identities has been introduced. If the pair alreadyexists in the cache, then the system uses existing information, andreplaces all of the Diameter relevant part of messages with thealternative. The alternative may be the local identity for the directiontowards the OCS, and the roaming identity for the reverse direction, orother relevant parts. If however, it is the first time that the identitypair has appeared then the system may obtain the relevant informationfrom the prepaid subscriber database, compose the new message andreplace the information.

An issue with retaining the data is to identify session termination,which is the last time the specific pair is to be used, so it can bedeleted from the memory. A solution may be to use a timer and identifyany sessions where there has been no active transactions, for apredetermined period of time, or explicitly identify session terminationmessages

A system for local prepaid service management may comprise a userinterface, prepaid account activation, and a top up system. The user mayaccess the system via web provisioning or SMS or any other communicationmeans. The user may enter his/her local prepaid card details, followingwhich the system may activate a new account, or top up an existingaccount. The system may associate the user roaming identity with a localidentity, and open the prepaid account using the local identity. Theprepaid system of the roaming network then handles the roamingsubscriber as if he/she is a local user belonging to the local network.

FIG. 7 thus shows a modification of the standard charginginfrastructure, in which the OCS Relay 150 and the OCS Proxy 154 enablethe local roaming prepaid system using the local OCS platform 152. It isnoted that the local OCS platform 152 may present in conventionallayouts for serving local subscribers.

In the above description of the OCS-Proxy 154, all charging of a localprepaid subscriber is routed to the local OCS 152. There may however bea scenario in which the data that is routed either to the home PDG (PDNGateway) or local PDG according to the routing decision, is divertedbetween the home network and the local network. Such a scenario is thewalled garden scenario referred to above, which may occur if, forexample, the data is addressed to the home portal of the operator, andcan be accessed only via the home PDG. The decision regarding home/localrouting is made by the GTP-relay 32 as discussed above. The OCS-relaymay thus simply follow the GTP-Relay decisions, and route the Diametercharging messages accordingly, splitting them between the home andvisited OCSs. The internal database of the GTP-Relay, which stores allcurrent active sessions, may be made accessible to the OCS-Relay aswell, so that inspection of the GTP relay database is all that isnecessary to determine which session or part of the session is routed tothe home network and which is routed to the visited network.

It is appreciated that certain features of the invention, which are, forclarity, described in the context of separate embodiments, may also beprovided in combination in a single embodiment. Conversely, variousfeatures of the invention, which are, for brevity, described in thecontext of a single embodiment, may also be provided separately or inany suitable subcombination.

Although the invention has been described in conjunction with specificembodiments thereof, it is evident that many alternatives, modificationsand variations will be apparent to those skilled in the art.Accordingly, it is intended to embrace all such alternatives,modifications and variations that fall within the spirit and broad scopeof the appended claims. All publications, patents, and patentapplications mentioned in this specification are herein incorporated intheir entirety by reference into the specification, to the same extentas if each individual publication, patent or patent application wasspecifically and individually indicated to be incorporated herein byreference. In addition, citation or identification of any reference inthis application shall not be construed as an admission that suchreference is available as prior art to the present invention.

What is claimed is:
 1. Apparatus for local access to data while roamingwith a mobile telephony device at a roaming network, the telephonydevice being associated with a home network separate from said roamingnetwork, the apparatus being located at said roaming network andcomprising: a filter having a data packet inspection unit for inspectingpackets to identify data packets addressed from said roaming telephonydevice for use via a home network data packet gateway, and a packetdiverter for diverting at least some of said identified packets to alocal data packet gateway; said filter being further configured to setup a diversion tunnel for additional packets having packet destinationinformation corresponding to said diverted packets, said diversiontunnel being for locally routing said packets having correspondingpacket destination address information to said local data packetgateway, wherein said filter is contained in a GTP signaling relay, anddata is channeled from said roaming mobile device to said relay via aserving GPRS support node—SGSN, wherein a data packet gateway comprisesa GGSN—said relay comprising an SGSN/GGSN emulator, emulating an SGSN tothe home network GGSN and a GGSN to the roaming network SGSN. 2.Apparatus according to claim 1, wherein said filter is configured toextract said packets from a data tunnel to said home data packet gatewayand to create a continuation of said data tunnel to said home datapacket gateway alongside said diversion tunnel.
 3. Apparatus accordingto claim 1, wherein said filter is configured to initially divertpackets, and to cancel said diversion when said diverted packets attractaccess refusals and to re-send the packets to said home data packetgateway.
 4. Apparatus for local access to data while roaming with amobile telephony device at a roaming network, the telephony device beingassociated with a home network separate from said roaming network, theapparatus being located at said roaming network and comprising: a filterhaving a data packet inspection unit for inspecting packets to identifydata packets addressed from said roaming telephony device for use via ahome network data packet gateway, and a packet diverter for diverting atleast some of said identified packets to a local data packet gateway;said filter being further configured to set up a diversion tunnel foradditional packets having packet destination information correspondingto said diverted packets, said diversion tunnel being for locallyrouting said packets having corresponding packet destination addressinformation to said local data packet gateway, said home networkproviding a subscription-based data service accessible through a portal,wherein said packet diverter is configured to select between packetsaddressed for said subscription-based service and packets addressed foruse outside of said subscription-based service, and diverting onlypackets intended for said outside use without the need for the homenetwork subscription, wherein said packet diverter is configured tocarry out said selecting by determining whether said packet contains aURL that maps to a portal of said home network.
 5. Apparatus accordingto claim 1, wherein said packet diverter is configured to divert byreplacing an address of the home data packet gateway or a nameidentifying the home gateway with an address of the local data packetgateway within said inspected message.
 6. Apparatus according to claim1, further comprising a packet return path for data packets to saidroaming mobile user, said return path configured to set all returningpackets to a given roaming mobile user to a same IP address. 7.Apparatus according to claim 1, wherein said diverted data packets arenotified to said home network for charging.
 8. Apparatus according toclaim 7, wherein call data records are sent to said home network forsaid charging.
 9. Apparatus according to claim 1, further comprising anOCS relay to decide whether to charge said roaming device at the homenetwork or at the local network.
 10. Apparatus according to claim 9,wherein said decision to charge is based on a presence or absence of asubscription of the roaming device at the local network.
 11. Apparatusaccording to claim 1, wherein a charging relay is provided at said localnetwork for managing charging for said data, said charging relay beingassociated with said filter to send charges for said diverted data tosaid local network and to send charges for other data to said homenetwork.
 12. Apparatus according to claim 4, wherein said filter iscontained in an MIP or a PMIP signaling relay.
 13. Apparatus accordingto claim 4, wherein said packet diverter is further configured to detectwhen diverted packets return a no access error, to cease to divertpackets corresponding to said no access error, and to re-send saidcorresponding packets to their original address.
 14. Apparatus for localaccess to data while roaming with a mobile telephony device at a roamingnetwork, the telephony device being associated with a home networkseparate from said roaming network, the apparatus being located at saidroaming network and comprising: a filter having a data packet inspectionunit for inspecting packets to identify data packets addressed from saidroaming telephony device for use via a home network data packet gateway,and a packet diverter for diverting at least some of said identifiedpackets to a local data packet gateway; said filter being furtherconfigured to set up a diversion tunnel for additional packets havingpacket destination information corresponding to said diverted packets,said diversion tunnel being for locally routing said packets havingcorresponding packet destination address information to said local datapacket gateway, wherein said filter is contained in a GTP singlingrelay, wherein said networks are all-IP networks wherein data ischanneled from said roaming mobile device to said relay via a servinggateway, and wherein a data packet gateway comprises a PDN gateway, saidrelay comprising an serving gateway/PDN gateway emulator, emulating aserving gateway towards the home network PDN gateway and a PDN gatewaytowards the roaming network serving gateway.
 15. Apparatus according toclaim 14, wherein said diverted packets are diverted towards a localbreakout at a local PDN gateway alongside voice packets.
 16. Method forproviding local access to data while roaming with a mobile telephonydevice at a roaming network, the telephony device being associated witha home network separate from said roaming network, the method beingcarried out at an electronic processor on said roaming network andcomprising: inspecting packets to identify data packets addressed fromsaid roaming telephony device for use via a home network data packetgateway; diverting at least some of said identified packets to a localdata packet gateway; and setting up a diversion tunnel for additionalpackets having packet information corresponding to said divertedpackets, said diversion tunnel directly routing said packets having saidcorresponding packet information to said local data packet gateway,wherein said inspecting packets is carried out at a GTP signaling relay,data being channeled from said roaming mobile device for said inspectingvia a serving GPRS support node—SGSN, wherein a data packet gatewaycomprises a GGSN—said relay comprising an SGSN/GGSN emulator, emulatingan SGSN to the home network GGSN and a GGSN to the roaming network SGSN.17. The method of claim 16, further comprising extracting said packetsfrom a data tunnel to said home data packet gateway and creating acontinuation of said data tunnel to said home data packet gatewayalongside said diversion tunnel.
 18. The method of claim 16, comprising:initially diverting packets as a default setting; and cancelling saiddiversion when ones of said diverted packets attract access refusals,and following said cancelling, sending said ones of said divertedpackets to an original destination.
 19. The method of claim 16, saidhome network providing a subscription data service accessible through aportal, the method comprising: selecting between packets addressed forsaid subscription data service and packets addressed outside of saidsubscription data service; and diverting only those packets addressedoutside of said subscription data service.
 20. The method of claim 19,comprising carrying out said selecting by examining layer 7 data of saidpacket to find a URL and determining whether said URL maps to a portalof said home network.
 21. The method of claim 16, wherein said divertingcomprises exchanging an address of the home data packet gateway or aname identifying the home gateway with an address of the local datapacket gateway within an inspected header.
 22. The method of claim 16,further comprising a packet return path for data packets to said roamingmobile device, the method comprising setting all packets in said packetreturn path of a respective roaming mobile user to a same IP address.